Switching device with moving parts in the form of a cross

ABSTRACT

An electromagnetic switching device having a built-in unit consisting of a cross-shaped magnetic circuit element adapted to selectively cooperate with the poles of at least two magnetic circuits and having at least one contact element which may be driven by the magnetic circuit element towards one of two positions so as to selectively close at least two corresponding electrical circuits.

United States Patent Preux Inventor: Roger G. Preux, 27, rue dEaubonne,St.

Gratien, France Sept. 23, 1970 Filed:

Appl. No.:

Foreign Application Priority Data [4 1 Mar.28,1972

Primary Examiner-Harold Broome Attorney-Waters, Roditi, Schwartz &Nissen Sept. 29, 1969 France ..6933124 ABSTRACT An electromagneticswitching device having a built-in unit US. Cl ..335/203, 335/180 7consisting of a cross shaped magnetic circuit element adapted Int. Cl. II to selectively cooperate the poles of at least [wo magnetic Field ofSearch Y circuits and having at least one contact element which may be335/229, 234, 203 driven by the magnetic circuit element towards one oftwo positions so as to selectively close at least two corresponding m Aelectrical circuits.

6 Claims, 5 Drawing Figures 2.4 X 7 i 1 11 s 8 F 1mg 4' 5i; W l/ 4 :P 11f z Y i T j/ 3 q; I 92:. 14-? 2 @61 10 B 4 j:- \z/ 44 4/ L l l l\ lPATENTED MAR 2 8 I972 SHEET 1 BF 2 SWITCHING DEVICE WITH MOVING PARTS INTHE FORM OF A CROSS The present invention concerns an electro-mechanicor electro-magnetic switching device with moving parts made up ofseveral elements of different materials and forming a unit in the formof a cross.

Systems of electro-mechanic or electro-magnetic switching are known,such as relays in which the commutation is effected by means of movingparts pivoting around apivot mounted on a bearing. In these relays, thearticulation on a level with the pivot must be carefully carried out sothat the speed of switching is not excessively reduced by friction. But

in any case the effect of friction cannot be reduced beyond acertainlimit. Such a relay is, then, at the same time relatively costly, clumsyand insufficiently rapid of function.

Relays are also known in which the moving parts are constitutedessentially of a single element playing the roles of magnetic switchingelement and contact element. Now, a magnetic switching element must beconstructed of a material best suited from the point of view ofmagnetism, permeability and retentivity, while a contact element must beessentially a good conductor, supple and elastic. In practice, thematerial constituting the single element is but imperfectly endowed withthe set of qualities needed for the switching and for the contact.

The aim of the present invention is to remedy these disadvantages and,to do this, it has as object a switching device with moving partsdistinguished in that the moving parts are constituted by a built inunit, freely placed, by at least one of its points and to the exclusionof pivots and hearings, on a support on which it rocks between twoswitching positions, the said unit comprising at least one magneticcircuit element capable of cooperating selectively with the poles of atleast two magnetic circuits and at least one contact element driven bythe magnetic element towards one of the two positions in order to closeselectively at least two corresponding electrical circuits, the saidelements forming together a unit in the form of a cross.

The advantage of such an arrangement is that it does away with the needof a spindle or a rotating pivot for the moving parts; indeed, when themagnetic element is attracted or repelled magnetically, the moving partsare limited in their movement towards the extreme positions only bytheir two elements appreciably orthogonal which ensure crossed guides.The movement of the moving parts is limited following two perpendicularaxes, one relating to the contacts of the electric circuits and theother to the supports for the poles of the magnetic circuit. The absenceof pivots results in a great simplification of the construction of theswitching device and therefore a notable decrease in its cost price. nthe other hand, because the moving parts are constituted of two elementseach playing a well-defined role, it becomes possible to construct eachof these elements in the material which is best suited to its function.For the magnetic element material will be chosen having the bestproperties from the point of view of magnetism, permeability andretentivity and for the contact element material which is supple,elastic and a good conductor of electricity.

Thanks to the switching device according to the invention, it becomesequally possible to use for the moving contact nonplated materialsensuring a longer life and a better quality of switching. Thesuppression of the pivots and bearings allows miniaturization of themoving parts and consequently an increase in the speed of switching.Moreover, the invention is applied to parts which rock, as much aroundone of their ends as around their centre of gravity or around anintermediate point. It applies also to every system ofelectro-mechanical or electro-magnetic switching and more especially torelays.

Advantageously, the unit of moving parts of elements of fixed contactsand poles are enclosed in an insulated case. So the switching can takeplace sheltered from external pollution.

According to one particular method of putting the invention into effect,the magnetic element rests on one extremity in a recess provided on apole common to the two magnetic circuits whilst the other extremity isattracted alternatively towards the poles of the magnetic circuits, thecontact element being driven by this movement, striking alternativelythe fixed contacts housed in the insulated case.

Because of this arrangement the position of the moving parts is assuredsince it is limited, in one direction, by the support of the movingcontact on the fixed contacts of the electric circuit and, in theperpendicular direction, by the support of the moving magnetic elementon the housing and on the pole of the magnetic circuit. It will benoticed that a fault of position of the moving parts is allowed in thetwo directions because if there is slipping of the latter, the supportof the contacts and the magnetic coupling remain nevertheless ensured inperfect conditions.

On the other hand, the movement of the moving parts following the firstdirection is determined by the equality of the reactions of the contactsexerted on the corresponding fixed contacts, which implies the equalityof these reactions which guarantees identical contact pressures. Aresult of that is that the moving magnetic element is helped in itschange of position by the couple produced by these contact reactions.

It is advantageous that the magnetic circuits are excited selectively bysingle or double coils fed by reversible direct current. It will benoted in any case that this method of excitation is not limiting.

According to another method of putting the invention into effect, themoving parts are capable of pivoting around the conjunction of themagnetic element and the contact element, the movement of the partsbeing limited in each switching position by two poles of the magneticcircuit and by two fixed contacts.

The switching device according to the invention is at the same timeeconomical, of simple construction and of assured functioning.

In any case the invention will be better understood referring to thedescription made with regard to the accompanying drawings, given solelyas an example and in no way limiting, and in which:

FIG. 1 is a plan view of a first method of effecting a relay accordingto the invention, the cover of the case having been removed.

FIG. 2 is a section following line IIII of FIG. 1.

FIG. 3 is a plan view of a second method of effecting a relay accordingto the invention.

FIG. 4 is a similar view of a third method of effecting the relayaccording to the invention and FIG. 5 is a perspective view of a fourthmethod of effecting the relay according to the invention.

FIGS. 1 and 2 represent a relay showing the bases and principles of theinvention. The relay comprises essentially a builtin moving switchingelement, formed by the unit of a magnetic circuit moving element 1 and asupple element 2 consisting of a flexible blade or wire. At the ends ofthe blade 2 are built up the contact elements 3 and 4. The method ofassembling these different elements is not restrictive; they can befixed by soldering, brazing riveting, by adhesive or by theinterplacirig of one or several conducting or insulating parts, theincorporation of several insulating pieces allows, with the help of asimilar moving magnetic element, the switching of several separatecircuits thanks to the multiplicity of supple elements and of contacts.There will also be seen in the figures a core 5 in which a housing 6 isfitted, having an appropriate shape and serving as articulation joint ofthe moving parts. A space or diametrical play will be provideddimensionally and axial play between the end of element 1 and the wallof the housing 6.

The magnetic circuit is made up of poles 7 and 8, coils'9 and 10, singleor double according to the electrical function to be obtained, a magnet11, opposite poles l2 and 13 and fixed contacts 14 and 15 for oneposition of the equipment, 16 and 17 for the other position. In certaincases of application or for reasons of sizing, the fixed contacts 14,l5, l6 and 17 are slightly supple or effected by blades; blade 2 canthen be rigid.

As can be seen in FIG. )1, blade 2 is subjected to a reaction couplefrom the contacts 14 and 15, following the arrows f. This couple isbalanced by the magnetic action F of pole 7 and by the reaction R of thesupport of the housing 6. The position of the moving parts is ensured,following an axis X identical with the axis of the magnet 11, thanks tothe support of the blade 2 between the contacts 14 and 15, and followingaxis Y perpendicular to axis X, thanks to the support of the pole 7 andof the housing of the core 5.

The moving parts, the fixed contact elements and the poles whichsurround them are located inside an insulated case so that switching canbe effected, sheltered from outside pollution. The insulated chamber ismade up by the assembly of a piece 18 and two covers upper and lower 19and 20 visible in FIG. 2. The method of assembling is not restrictive;they can be stuck, soldered, sealed, crimped or closed mechanically. Thecovers constitute the basic parts receiving the fixed contacts as wellas walls 21 and 22 limiting laterally the moving parts. As shown in FIG.2, the fixed contacts are made up of elements built up by soldering onthe output pins, which allows easy manufacture of the covers, withoutimpairing the contacts, and which limits the contact materials to verysmall dimensions thus encouraging a reduction in construction costs.

When working, in the position represented in FIG. 1, the moving magneticelement 1 is coupled to the magnetic circuit made up of the pieces 1, 7,ll, 12 and the cores of the coils. If the coils 9 and 10 are actuated soas to polarise the extremity of pole 7 with a polarity identical to thatproduced by the magnet and opposed to that of the extremity of pole 8,element 1 will be repelled by pole 7 and attracted by pole 8; the relaywill then have switched another circuit. This change of position can beproduced, according to suitable dimensions, by the momentary orpermanent action of the excitation. It is the method of bistable workingassuring the memory of the excitations. In the case where a monostableworking is desired, it would be well to suppress one of the couplings,for example element 12 or element 13 and to actuate the coils in anappropriate way.

Such a relay offers multiple advantages among which may be quotednotably:

The simplification of the construction of the relay particularly becauseof the absence of pivots and bearings; the moving parts, on the otherhand, may or may not comprise seperate contacts 3 and 4;

The use for the magnetic element 1 of a material which is best andsolely suited for the magnetic functions and its permeability; it is thesame for the moving switching element which serves only the function ofsupport and can consequently be chosen to fulfil best these conditions;in the same way, contacts 3 and 4 will be adapted to the sole functionof switching;

The possibility of using for the moving contact non-plated materials,which leads to a longer life and better quality of switching;

The miniaturization of the moving parts and consequently the rapidmovement of the parts between the two switching positions;

The natural balance of contact pressures in the switched circuit; themovement of the moving parts following axis X, for example, isdetermined by the equality of efforts on contacts 14 and H5;

The certainty of having a correct coupling of the magnetic pieces andidentical contact pressures. A fault of position of contacts I4 and E5is permitted by movement following axis X of the mobile part; in thesame way a fault in position of pole 7 or of the housing 6 is permittedby movement of the moving parts following axis Y. This fault of positionis transformed into a reciprocal slipping but the support of thecontacts and the coupling remain assured;

The possibility of enclosing the contacts and the moving parts in aninsulated case because of the small dimensions of the moving parts;

The simplification of construction of the supple contacts and The use ofthe reaction of the contact support as an additional force, at the timeof change of position of the magnetic element 1; as soon as anopposition of field is produced by one of the windings, the magneticelement 1 switches and is helped in its change of position by the coupleproduced by the reactions f of the contacts.

The family of relays thus produced can work following different methodsof excitation, according to the functional properties of the inventionand the needs of industrialization.

FIG. 3 represents a second method of producing a relay constructedaccording to the principles of the invention. The relay comprises aferrite rod 25, opposite poles 26 and 27, a coil whose core 28 serves asarticulation for the moving magnetic element 29 integral with a movingcontact element. This latter rocks between fixed contacts 311, 32 and33, 34 inside an insulated case 35.

FIG. 4 represents a lay-out in which the moving element in form of across is made up of a magnet or a ferrite rod 40 and a supple contactelement. This part is capable of rocking between fixed contacts 42, 44and 43, 45. The extremities of the cores 48 and 49 of coils 46 and 67make up the poles on which the magnetic element 410 rests.

FIG. 5 represents another method of production in which the mobileelement in the form of a cross is made up of a moving magnetic element60, a supple moving contact element 611 and a built-in element 62serving, on the one hand, to polarise the magnetic element 60 bytransmitting the field of the coils excitation 63, and on the other handto ensure the articulation of all the parts in a hole 64 in the core ofthe coil 63. In this figure are found fixed poles made up of ferriterods 65, 66, 67 and 68 as well as fixed contacts 69, 70, 71 and 72. Aunit of contact and ferrite rod in the form of a cross could be fittedat each end of the coil. The number of contacts is then doubled and thepivot 64 suppressed.

Although the magnetic circuits of the last three methods of productionare different from that of FIG. 1, the basic principles neverthelessremain, the properties and advantages of the invention are all retained.

Moreover it goes without saying that numerous modifications of detailcan be used in the methods of production described, notably bysubstituting equivalent technical methods, without departing for allthat from the outline of the invention. For example, the number ofmobile elements, contacts, magnets, coils and magnetic circuits could bemultiplied. The magnet could be replaced by ferrite rods or by excitingcoils. Moreover, several insulated contacts could be associated on themoving elements. Lastly, moving parts in the fonn of a double cross or aT could be produced, but retaining the double guiding system accordingto the invention.

What I claim is:

1. An electrical switching device, comprising in combination, a magneticelement, a contact element, said two elements being assembled to form abuilt-in cross-shaped unit and being constituted from materials ofdifferent natures adapted to their respective magnetic and contactfunctions, a support for said unit, at least two magnetic poles havingstationary contacts contacted by said element, at least two electricalcircuits, the said cross-shaped unit being freely supported, by at leastone of its points on said support so as to rock between two switchingpositions, said contact element in said positions being able toselectively close one of the said electrical circuits while saidmagnetic element selectively cooperates with one of the said magneticpoles.

2. Switching device according to claim 1, including a housingencompassing the magnetic element, a pair of magnetic circuits each ofwhich terminates in a pole, whose polarity is induced by the excitationproduced by a coil surrounding an element of each of the magneticcircuits, one extremity of the magnetic circuit being supported on apole common to said circuits the second extremity of the magneticelement being attracted alternately towards one of the said poles, thecontact element being driven by this movement so as to strike thestationary contacts.

3. Switching device according to claim 1, including a housingencompassing said magnetic element, an exciting coil, having a core, oneextremity of the element supported on the end of the core, the otherextremity of the magnetic element being capable of being selectivelyattracted by the magnetic poles, said poles being joined by a ferriterod.

4. Switching device according to claim 3, characterized in that themagnetic circuits are selectively excited by single or double coils,actuated by reversible direct current.

5. Switching device according to claim 1, wherein said cross-shaped unitis capable of being pivoted about a point remote from its ends, such asa point in proximity to its center of gravity or around the point ofconjunction of the magnetic and contact elements, the movement of themoving parts being limited, at each switching position, by two magneticpieces and by two fixed contacts, according to two axes appreciablyorthogonal.

6. Switching device according to claim 1, including an insulated caseenclosing the unit of movable elements, fixed contact elements andpoles.

1. An electrical switching device, comprising in combination, a magneticelement, a contact element, said two elements being assembled to form abuilt-in cross-shaped unit and being constituted from materials ofdifferent natures adapted to their respective magnetic and contactfunctions, a support for said unit, at least two magnetic poles havingstationary contacts contacted by said element, at least two electricalcircuits, the said cross-shaped unit being freely supported, by at leastone of its points on said support so as to rock between two switchingpositions, said contact element in said positions being able toselectively close one of the said electrical circuits while saidmagnetic element selectively cooperates with one of the said magneticpoles.
 2. Switching device according to claim 1, including a housingencompassing the magnetic element, a pair of magnetic circuits each ofwhich terminates in a pole, whose polarity is induced by the excitationproduced by a coil surrounding an element of each of the magneticcircuits, one extremity of the magnetic circuit being supported on apole common to said circuits the second extremity of the magneticelement being attracted alternately towards one of the said poles, thecontact element being driven by this movement so as to strike thestationary contacts.
 3. Switching device according to claim 1, includinga housing encompassing said magnetic element, an exciting coil, having acore, one extremity of the element supported on the end of the core, theother extremity of the magnetic element being capable of beingselectively attracted by the magnetic poles, said poles being joined bya ferrite rod.
 4. Switching device according to claim 3, characterizedin that the magnetic circuits are selectively excited by single ordouble coils, actuated by reversible direct current.
 5. Switching deviceaccording to claim 1, wherein said cross-shaped unit is capable of beingpivoted about a point remote from its ends, such as a point in proximityto its center of gravity or around the point of conjunction of themagnetic and contact elements, the movement of the moving parts beinglimited, at each switching position, by two magnetic pieces and by twofixed contacts, according to two axes appreciably orthogonal. 6.Switching device according to claim 1, including an insulated caseenclosing the unit of movable elements, fixed contact elements andpoles.